Manufacture of brake drums



Nov. 15, 1938. F. H. LE JEUNE 2,136,447

MANUFACTURE OF BRAKE DRUMS Filed May 25, 1936 [A'l TIM FRANK H. LEJEUNE A TTUANE J S Patented Nov. 15, 1938 PATENT OFFICE MANUFACTURE OF BRAKE DRUMS Frank H. Le

Jeane, Detroit, Mich, assignor to Kelsey-Hayes Wheel Company, Detroit, Micln, a corporation of Delaware Application May 25, 1936, Serial No. 81,754 2 Claims. 22-403) This invention relates to the manufacture of composite brake drums, and more particularly to casting metal around connecting means which forms a bond with the brake ring portion of the drum and with the web portion as well, the lat- :ger being poured prior to pouring the, ring por- In the present invention, the complete brake drum may be cast in a mold without disassembly of the mold, the web portion being poured separately from a ring having a braking surface portion thereon. Means are provided to separate the cavities in which the ring and web portions are formed to preclude or retard flow from one cavity to the other, thereby making it possible if desired, to cast the respective portions of the brake drum simultaneously At the same time, the separator is so formed and positioned in the mold that it is embedded in the ring and web portions and forms a bond and connection therebetween.

The invention will be further understood from the following description thereof, the accompanying drawing illustrating a preferred form of apparatus for carrying out the method.

In the drawing:

Fig. l is a sectional elevation of a mold embodying the features of the present invention;

Fig. 2 is a fragmentary section of a modified form thereof;

Fig. 3 is a iragmentarysectional view of theconnecting ring.

Referring to the drawing, it will be seen that the type of wheel to which the invention is particularly applicable, comprises a brake drum in cluding a brake ring portion 6, the inner periphery of which forms a braking surface, a web portion 1 having an annular flange 8 extending radially therefrom towards the brake ring portion, and an annular ring 9 connecting the brake ring and web portions. The brake ring is formed from a metal particularly adapted for braking surfaces, while the web and'its flange are pref erably formed from a different metal more suitable to resist stresses set up in the web portion. The ring and brake may, however, be cast from the same metal. These two portions of the brake drum are spaced from each other in the embodiment shown in the drawing, the space between them being bridged by the ring 9, the peripheral edges of which are embedded in the web and brake ring portions respectively, forming a bond therebetween and connection between the said portions.

The mold in which the composite brake drum is cast is a multi-part mold comprising flasks l0 and H wherein are held a drag l2 and cope l3, between which annular cavities I4 and I5 are formed. It is to be noted that the cavities and 15 are spaced and separated from'each 5 other, there being disposed in the space between and bridging the cavities the web l6 of the annular separator or connecting ring 9, the cross section of which is preferably Z-shaped, as shown in the drawing. Sprues I! and I8 having gates 10 I9 and 20, direct the poured metal into cavities I 4 and respectively. The usual core 2|, providing an axial opening through the hub, and a core 22 forming a gate for the cavity l4, coopcrate with the drag and cope to complete the 15 mold. Because the cavities M and I5 are spaced from each other and ring 9 acts as an obstruction to preclude flow of metal from one cavity to the other, it is obvious that different metals may be poured into the respective cavities without disassembly of the mold. If desired, the pouring of the parts of the drum may be done simultaneously without danger of inter-mixture of the metals. The ring 9, in addition to its function as a separator between the cavities, forms the 25 connecting element between the ring portion 6 and web portion 1 of the brake drum. The flanges 23, 24 of the ring project respectively into cavities l4 and I5, being so positioned therein that, when metal is poured into each of the cavities, a bond is formed between both sides of each flange with the metal poured therearound.

In the form of the invention disclosed in Fig. 1, grooves 25 are provided whereby ribs 28 are formed on brake rings 6. The latter is machined after removal from the mold, to provide an accurate cylindrical braking surface, as indicated by the broken line 21. In Fig. 2 there is shown another embodiment of the brake ring which is machined after casting to form ribs as 40 indicated by the broken line 28. In both forms of the invention, however, the method of casting the brake drum is the same.

From the foregoing description it will be seen that the casting of composite brake drums is simplified, the casting of the brake ring and web portions may be done simultaneously, or substantially so, and that the entire operation may be carried out in a single mold without disassembly of the mold or removal of any of the parts thereof. At the same time an efl'ective connection between the ring portion 6 and web portion I of the drum is made during the casting operation and, when removed from the mold, the

wheel is a complete unit.

A preferred method and apparatus for carrying out the invention has been described, but it is intended that such changes as are deemed expedient to successful operation thereof be included in the scope of the appended claims. The connecting ring, for instance, is shown as Z- shape in section, but it is obvious that other shapes may be employed to effect a similar connection. Also, instead of the openings in the flanges, as shown in Fig. 3, the peripheral edges of the ring may be provided with dove-tail notches.

What I claim as my invention is:

1. The method of casting brake drums having separated web and braking surface portions which consist in forming spaced web and braking surface cavities in a mold, preventing the flow of metal from one cavity to the other by positioning a connecting ring in the mold with the inner and outer portions of the ring extending into the cavities, and casting the web and braking surface portions on the connector with the said inner and outer portions embedded respectively in the web and braking surface.

2. The method of casting a brake drum provided with a. web and a flange having a portion forming a. braking surface which consists in forming web and flange cavities in a sand mold, positioning a ring in the mold to preclude flow from the web cavity to the braking surface portion of the flange cavity, providing a passage for molten metal in the mold with the discharge end thereof communicating with the web cavity to one side of the ring, and providing a second passage in the mold with the discharge end communicating with the flange cavity at the opposite side of the ring.

FRANK H. LE JEUNE. 

